In the Marble Runs unit, designed for grades 4-5, students are introduced to a real-world
problem: a toy inventor’s marble run keeps getting stuck, and the ball doesn’t roll to the end. It’s up to the class to figure out why and design a marble run that can keep a ball rolling for five seconds or more.

Through a series of four hands-on, standards-aligned investigations, students explore how ramps, slopes, friction, and collisions affect the motion of a rolling ball. They test different ramp angles to see how steepness changes speed, add bumpy surfaces to explore how friction slows motion, and extend tracks to investigate how distance affects rolling time. Just like scientists, they ask questions, carry out fair tests, collect and analyze data, and construct explanation from their results. They see how a ball starts to roll when forces are unbalanced, how it speeds up or slows down depending on the slope, and how a faster-moving ball hits harder and can knock things over.

In the five final lessons, following the Engineering Design Process, students work in
partnerships to design and build their own marble runs. Just like engineers, they brainstorm solutions, sketch ideas, build prototypes, and then test, refine, and present their creations. The final marble runs–built from cardboard boxes, paper tracks, cups, and tape–send balls twisting, turning, jumping, and rolling to the finish, showing how scientific understanding and creativity come together in exciting designs.